critical fix reference to default method, set to null so it will not be copied between mixins
critical fix reference to default method, set to null so it will not be copied between mixins

Enyo-DCO-1.1-Signed-off-by: Cole Davis <cole.davis@palm.com>

beni55/enyo,zefsolutions/enyo,mcanthony/enyo,bright-sparks/enyo,kustomzone/enyo,PKRoma/enyo,PKRoma/enyo,soapdog/enyo,kustomzone/enyo,wikieswan/enyo,wikieswan/enyo,airspringsoftware/enyo,beni55/enyo,bright-sparks/enyo,enyojs/enyo,airspringsoftware/enyo,enyojs/enyo,zefsolutions/enyo,mcanthony/enyo,soapdog/enyo